Ground anchor



Jan. 13, J. P BURKE GROUND ANCHOR Filed July ll, 1940 ATTORNEY.

Patented Jan. 13, 1942 OFFICE GROUND ANCHOR `lames P. Burke, Knoxville,Tenn., assigner of one-half to John W. Greene, Knoxville, Tenn.

Application July 11, 1940, Serial No. 344,953

4 Claims.

This invention relates to a ground anchor or so-called dead man and hasfor its primary object to provide an improved means for anchoring staycables such as are used in conjunction with telegraph, telephone andpower poles, bridge cables, and for such other uses as require theanchoring of a cable or similar means to the ground.

Use of many types of conventional ground anchore, such as some of thosehaving hinged wing-like portions, requires that a hole be dug in orderto enable placement of the anchor beneath the surface of the ground, andthis hole must be large enough to permit expanding of the wing-likeportions after placement of the ranchor. After the anchor is so placedit is necessary to replace the soil and tamp it rmly in place. Thismethod of placing the anchor requires considerable labor and in additionit is found that results are not satisfactory because of the fact thatthe soil has been disturbed and an excessive pull on the anchor willcause loosening thereof. This invention has for its object to provide aground anchor which avoids the objections above mentioned by avoidingthe necessity of digging a hole and thereby eliminating any tendency forloosening of the anchor because of the presence of disturbed soil.

More specically, the object is to provide an anchor which may be driveninto the ground by means of a sledge hammer or the like, and means forexpanding a portion of the anchor after it has been driven into theground to prevent its removal therefrom. The means for expanding theanchor comprises a tubular body weakened in predetermined regions andmeans for ring an explosive charge in this region in such manner that ahigh internal pressure is developed and expansion of the weakenedportion of the tube results.

Other objects and advantages will become more fully apparent asreference is made to the accompanying drawing wherein my invention isillustrated, and in which Fig. 1 is an elevation of the anchor, prior toexpansion thereof,

Fig. 2 is a section of the anchor, with the driving member insertedtherein,

Fig. 3 is a section illustrating the explosive charge supporting andexploding means,

Fig. 4 is an elevation of the anchor in an expanded condition, and

Fig. 5 is a section illustrating a modified means for supporting andexploding an explosive charge.

The anchor comprises an elongate metal tube I having a pointed metalnose 2 welded thereto. The tube is weakened adjacent the nose 2 byformation of a multiplicity of grooves 3 or sawcuts, extending inparallel relationship, and in the direction of the length of the tube.At its other end the tube has external threads 4.

The anchor is driven into the ground by inserting a metal rod 5 into thetube I and into contact with the ilat end 6 of the nose member 2, andthen striking the rod with a Sledge hammer or the like. The anchorcould, of course, be driven int-o the ground by striking the end of thetube, but this would very likely injure the screwthreaded end of thetube.

After the anchor is inserted in the ground a cap 6 is screwed onto itsupper end. The cap 6 has an elongate tubular extension 'I integraltherewith. Welded in the lower end of the extension 'I is a body 8having an axial bore 9 slidably receiving a ring pin` I0. The ring pinextends upwardly through. an axial` bore IVI in the cap 6 and has aheadV I2 secured upon its upper extremity by a pin I3. A spring I4isinterposed between the cap 6 and the head I2 and urges movement of thefiring pin upwardly and normally maintains a collar I5 on the firing pinin contact with the lower sideof the cap 6.

The body 8 has a screwthreaded portion I6 receiving and removablysupporting a shell supporting member I1 having a bore I8 for receiving ametal portion I9 of a shell 20, and a shoulder 2| for engaging a flange22 on the upper end of the shell. The shell 20 may be imagined as beingsimilar to a conventional percussion type,

paper shot-gun shell, but without projectiles, of course.

To expand the anchor the head I2 is struck by a hammer or the like,thereby causing the firing pin to strike the percussion cap 24 and thelatter to explode the shell. The forces created by the explosion areentirely conned in the tube I which, therefore, expands in its weakestregion. The tube in its expanded condition is illustrated in Fig. 4,wherein it is illustrated that the metal of the tube separates along theweakened lines 3. Greater or lesser separation can be obtained byvarying the amount of explosive in the charge.

After the tube I has been expanded the cap 6 and complete ring mechanismis removed and a cap 25 is screwed onto the upper end of the tube. Thecap 25 has an eye 26 or some other suitable means for attachment of acable or the like thereto.

In Fig. 5 there is illustrated a tubular anchor 3B constructed identicalto the anchor i. In the lower end of the tube 3i) is welded aninternally threaded sleeve 3| into which the shell holder 32 is screwed.The shell holder 32 is screwed onto the lower end of an elongate ringpin support 33, and the metal flange yportion 34 of a shell 35 isclamped between a shoulder 36 in the shell holder 32 and the lower endof the firing pin support 33. 3'! therein and a finger 38 slidablymounted on the ring pin support engages in this groove to retain theshell holder against rotation. For replacement of a shell the finger 38is moved out of engagement with the groove 3T so that the shell holderYmay be unscrewed from the iring pin support.

In the support 33 is a firing pin 3S having a head 4i) on its `upper endand a spring lli is interposed between the head 49 and the upper end ofthe iiring pin support to normally hold the lower end of the ring pinspaced from the percussion cap of the shell 35. The shell 35 is ex-'ploded by striking the head 6d' with a hammer, and its explosion'causesexpansion of the tube E@ in a manner identical to that described inconnection with the tube l.

In the rst described form .the entire tubular anchor is subjected to thepressure of the eX-y plosion, whereas in the second described form onlythe lower portion is subjected to the pressure. Therefore, in the secondform it is not essential that the tube be weakened by grooves such asshown at 3, However, weakening of the tube is preferred because itresults in more uniform expansion.

Although specific embodiments of the invention have been illustrated anddescribed, it will be understood that various changes may be made withinthe scope of the appended claims without departing from the spirit ofthe invention, and such changes are contemplated.

What is claimed is:

1. An explosive holder for a ground anchor comprising an elongatetubular member having a cap on one end adapted to be secured to a groundanchor to seal the same, a removable shell holder on the other end ofsaid tubular member adapted to receive an explosive shell of the per-The shell holder 32 has a groover lar extension on said cap adapted tobe supported thereby within the ground anchor, a firing pin guide on theother end of said extension, a iiring pin having one end slidablydisposed in said guide and its other end extended through said cap,means for securing an explosive shell on the lower end of said guide forengagement by the adjacent endof said ring pin, and a spring yieldinglyholding said ring'pin retracted and spaced from an explosive so held.

3.. AAn explosive holder for a ground anchor comprising a cap adapted tobe secured on the upper end of a ground anchor, an elongate tubularextension on said cap adapted to be supported thereby within the groundanchor, a ring pin guide on the other end of said extension, a ring pinhaving one end slidably disposed in said guide and its other endextended through said cap, a shell supporting member removably securedat the end of said extension for supporting an explosive shell adjacentthel end oi said firing pin, and a spring yieldingly holding said ringpin in a retracted position.

4. An explosive holder for aground anchor, comprising a cap adapted tobe secured on the lupper end of a ground anchor, said cap having atubular extension extending axially thereof and adapted to be supportedby said cap in a position extending into the ground anchor on which thecap is to be secured, anringpin guide in the lower end of saidextension, a iiring pin received in said guide and extending upwardlythrough the extension and said cap, means on said ring pin for engagingsaid cap to restrict upward movement of the firing pin at a point wherethe lower end is in said guide, a spring yieldingly holding said firingpin in its upper position, and means for securing an explosive shell onsaid guide For engagement by the firing pin.

JAMES P. BURKE.

